In the real estate industry, a need exists for controlled access to homes for sale that is both flexible to serve the real estate professional and secure for the homeowner's peace of mind. The traditional method has been the use of a key safe or lock box that attaches to the homeowner's doorknob and contains the dwelling key. Many conventional designs ranging from mechanical to electronic have been used over the years to provide this functionality. Homeowners prefer electronic systems because, unlike their mechanical counterparts, the electronic systems offer greater security and control over whom has access to the dwelling key and further offers the ability to track accesses to the key.
Homeowners also desire control over the time of day accessibility to their home for showing appointments, and they often have a need to communicate special showing instructions to potential visiting real estate sales professionals. Such instructions can frequently include home security system shutoff codes, a special instruction such as, “don't let the dog out of the basement,” or other data pertinent to accessing the home. In addition, homeowners are reassured when they learn that all accesses to their dwelling key are recorded in a way that can identify the person accessing the key.
The needs of the real estate professional are as equally important as the needs of the homeowner. Accessing the secure compartment of the lock box must be easy to perform and there must be a simple way to manage multiple users who access multiple lock boxes. Programming lock box configuration information and retrieving access logs also needs to be simple and efficient.
The greatest challenge in previous designs has been the management and updating of electronic keys and electronic lock boxes with current access code information. The distribution of such information is compounded geometrically with the number of lock boxes and keys. This has not been a huge problem from the key side with the advent of central computer systems communicating with keys; however, conventional systems now in use have not addressed the fundamental problem of updating lock box devices that are dispersed over a large geographic area. The previous designs and prior art patent literature provide an updating function via a radio signal or a pager, however, these systems are impractical due to the receiving circuit's power drain and potential proximity constraints with respect to the physical locations of receiver and transmitter.
All of the convention electronic lock box systems have focused on loading electronic keys with access codes for use with lock boxes that could potentially be visited. In fact, these prior art systems have increasingly encompassed more costly and cumbersome electronic key solutions that are required to be periodically updated with new access codes.
It would be an improvement to provide a new method of access control of lock boxes using a simple to operate and manage system, using a new approach to the problem of access code synchronization between lock boxes and keys. Another improvement would be to provide an access code disclosure device that replaces conventional electronic keys, in which the access code disclosure device comprises a credit-card sized portable computer and a very thin secure memory card for a real estate agent for obtaining access to a lock box key compartment. A further improvement would be to use an access code that is randomly-generated in real time by the lock box.